London: map of number of measurements
Deciles of number of measurements:
(1.0, 3.0)
(3.0, 8.0)
(8.0, 15.0)
(15.0, 29.0)
(29.0, 53.0)
(53.0, 100.0)
(100.0, 185.0)
(185.0, 332.0)
(332.0, 740.0)
(740.0, 4247.0)